1. Field of the Invention
This invention relates to a method of registration of authorized agent information for a biometrics authentication device, an authentication method for a biometrics authentication device, and a biometrics authentication device, which uses biometrics characteristics of a portion of the human body, and in particular relates to a method of registration of authorized agent information for a biometrics authentication device, an authentication method for a biometrics authentication device, and a biometrics authentication device to permit individual authentication, by means of biometrics information, of an authorized agent other than the principal.
2. Description of the Related Art
There are numerous portions of the human body which can differentiate the individual, such as fingerprints and toe-prints, the retinas of the eyes, facial features, and blood vessels. With advances in biometrics technology in recent years, various devices have been provided which identify biometrics features of a portion of the human body to authenticate individuals.
For example, because blood vessels and prints of the palms and fingers of the hands provide a comparatively large quantity of individual characteristic data, they are suitable with respect to reliability of individual authentication. Blood vessel (vein) patterns in particular remain unchanged throughout life from infancy and are regarded as being completely unique, and so are well-suited to individual authentication. Of this, individual authentication technology based on blood vessel images in the palm of the hand is explained.
First, at the time of registration or of authentication, the user brings his palm into proximity with an image capture device. The image capture device emits near-infrared rays, which are incident on the palm of the hand. The image capture device uses a sensor to capture near-infrared rays rebounding from the palm of the hand. Hemoglobin in the red corpuscles flowing in the veins has lost oxygen. This hemoglobin (reduced hemoglobin) absorbs near-infrared rays at wavelengths near 760 nanometers. Consequently when near-infrared rays are made incident on the palm of a hand, reflection is reduced only in the areas in which there are veins, and the intensity of the reflected near-infrared rays can be used to identify the positions of veins.
The user first uses an image capture device to register vein image data of the palm of his or her own hand on a card. Then, in order to perform individual authentication, the user employs an image capture device to read the vein image data of his or her own hand. The registered vein image retrieved using the ID of the user is verified against the vein pattern of the vein image for verification thus read to perform individual authentication.
On the other hand, in the field of fingerprint authentication, a method of biometrics authentication of an authorized agent has been proposed in which fingerprint information for an authorized agent other than the principal is registered in advance, and by performing fingerprint authorization of the authorized agent, a single card can be used for biometrics authentication of an authorized agent (see for example Japanese Patent Laid-open No. 2001-067523 (FIG. 6, FIG. 7) and Japanese Patent Laid-open No. 2001-202494 (FIG. 2)).
In this technology of the prior art, an authorized agent who has received the consent of the principal can have his fingerprints registered, and can undergo individual authentication. In this method of the prior art, at the time of card issue, biometrics information of the principle and the biometrics information for the authorized agent are registered based on the authorization of the principal.
On the other hand, in an actual aspect there is the requirement that the biometrics information of the authorized agent be registered, modified, or deleted on a card on which the biometrics information of the principal has first been registered. Using the technology of the prior art, however, it is difficult to register, modify, or delete the biometrics information of the authorized agent securely to meet this requirement, and the security of biometrics authentication is impeded. Hence actual use is exceedingly difficult.